On 04/22/2025, Jason Gunthorpe wrote: > On Tue, Apr 22, 2025 at 02:55:28PM -0700, William McVicker wrote: > > > On this note, I was looking through `of_dma_configure_id()` and am also > > wondering if we may hit other race conditions if the device is still being > > probed and the dma properties (like the coherent dma mask) haven't been fully > > populated? Just checking if the driver is bound, doesn't seem like enough to > > start configuring the DMA when async probing can happen. > > I think the reasoning at work here is that the plugin path for a > struct device should synchronously setup the iommu. > > There is enough locking there that the iommu code won't allow the > device plugin to continue until the iommu is fully setup under the > global lock. > > The trick of using dev->driver is only a way to tell if this function > is being called from the driver plugin path just before starting the > driver, or from the iommu code just before configuring the iommu. > > Given that explanation can you see issues with of_dma_configure_id() ? > > Jason I think the only concern is when a driver calls dma_set_mask_and_coherent() in it's probe function. If we can handle that case in an asynchrounous manner, then I think we are good. Thanks, Will
